Ecological Trendofthe Incidence of Tuberculosis in Mianyang City During 2004-2013

OBJECTIVES:To determine the trend of the incidence of tuberculosis (TB) in Mianyang City during 2004-2013 and its ecological determinants. METHODS:Linear correlations between TB incidence and ecological factors were analyzed using the data collected in Mianyang City from 2004 to 2013. A multivariate linear regression model was established to determine the ecological predictors of TB incidence. RESULTS:The incidence of TB in Mianyang City decreased over the period of 2004-2013. Economic development and increased health resources were negatively correlated with TB incidence. Population density was positively correlated with TB incidence. A multivariate linear regression equationon TB incidence (y) was established with the independent variables (x₁ to x₁₀) forming a component (using principal component analysis) to eliminate multicollinearity: y=117.692-1.467x₁-1.145x₂-1.961x₃-4.777x₄-2.690x₅-6.181x₆+82.234x₇-2.721x₈-0.351x₉-0.382x₁₀. The incidence of TB decreased with the increases of real GDP per capita (x₁), average wage of workers(x₂), per capita disposable income of urban residents (x₃), rural per capita net income (x₄), per capita consumption expenditure of urban residents (x₅), per capita living consumption expenditure of rural residents (x₆), number of licensed (assistant) physicians per thousand population (x₈), urbanization rate (x₉),and per capita housing construction area of urban (x₁₀),while it increased with the increase of density of population (x₇). CONCLUSIONS:Socio-economic development, health resources and population density are predictors of TB incidence.